Removed obsolete TODO in proxy_model_inheritance test.

[htkuan]

I just see this TODO, I think it should be available.

[htkuan]

oh, I miscalculated top-level package, so just clear this todo.

[carltongibson]

Hi @htkuan.

As you'll see from the CI, this fails:

pr/python/python3.5/tests/proxy_model_inheritance/app1/models.py", line 1, in <module>
    from ..app2.models import NiceModel
ValueError: attempted relative import beyond top-level package

The failure shows up locally running the tests:

django/tests  $ ./runtests.py proxy_model_inheritance

Do you think you can debug what's going on here?

[htkuan]

ok! let me debug this.

[timgraham]

Removing the TODO comment seems fine to me.

[htkuan]

I know why can't use '''from ..app2.models import NiceModel''',
Because when call "proxy_model_inheritance/tests.py" file, it will make '_main_' is tests.py.
So when tests.py is '_main_' means dir(proxy_model_inheritance/) not a package.
It cause:

1. tests.py line.25~26 can't use relative imports
2. app1/models.py top level package root is app1, so it can't use relative import to find app2
3. app1/models.py only can use absolute import to find app2